I just put the 304 system on my '05 w/o the cat. Sounds great. Real throaty at low RPM's. Loud, but not too loud when I wind it out. EGT's seems to run about the same, but cooled down alot faster with the new system. Turbo seems to spool up just a tick quicker. Fit and finish are excellent. All hangers aligned perfectly. The only feature I didn't like was that they provide a small section of pipe that needs to be trimmed if you don't have a long bed or mega cab. Mine ended up being only about 6" for the short bed. I think they could have configured a longer cat delete pipe to compensate for short beds. Otherwise, I like it.